I don't think it constitutes state aid. West Ham are merely leaseholders on the stadium and the stadium is also available to other leaseholders.
I had a feeling I had read somewhere that the conversion cost could be deemed to be state aid... from the Guardian this time last year:
London Assembly members, European state aid experts and lawyers have questioned why the mayor of London, Boris Johnson, and the London Legacy Development Corporation did not obtain “prior approval” from the European Commission before signing the deal with West Ham.
One London Assembly member claimed the LLDC was “in denial” while several state aid experts consulted by the Guardian said it would have been “prudent” to gain approval to avoid problems down the line.
By not getting the agreement signed off before concluding the deal with West Ham, the LLDC has left itself open to a 10-year window for challenges from anyone who feels disadvantaged by West Ham’s deal, understood to be worth £2.5m a year plus a slice of catering revenues.
That could include rival clubs at home and abroad and, if the EC eventually found the LLDC had broken state aid rules, West Ham could be liable for millions. Theoretically, if found in breach the total bill could equate to the £138.9m it is costing the public purse to convert the stadium for football use plus the difference between the £2.5m and whatever the EC decided the market rate was.
The controversial saga that led West Ham to be awarded a 99-year licence agreement last year was marked by legal challenges, espionage allegations and furious rows over the legacy and cost. In October it emerged the total cost of the stadium had risen to £619m, including the post-Games conversion to install retractable seats and a full roof after the construction of the cantilevered canopy had turned out to be more expensive than expected.
As well as paying a fee understood to be in the region of £2.5m for their licence agreement, West Ham also agreed to pay £15m towards the £193.9m conversion costs and argues that its presence will help raise more from naming rights. The rest of the cost of building the stadium and converting it into a “multi-use” arena has been met from public funds.
Information obtained by the Charlton Supporters Trust under the Freedom of Information Act and seen by the Guardian shows West Ham’s £15m contribution does not have to be paid until the club receive the proceeds from the sale of Upton Park.